| 摘要 |
PROBLEM TO BE SOLVED: To provide a compact structure for quickly precooling and effectively preventing the entry of heat into a body to be cooled after precooling. SOLUTION: A refrigerant piping wherein refrigerant is circulated is provided by using a refrigerator 16 provided with a first cooling end 22 and a second cooling end 26 whose refrigeration capacity and cooling temperature are lower than those of the first cooling end 22, and at a midpoint thereof, a first heat exchanging part 53 for heat exchanging between the first cooling end 22 and refrigerant and a second heat exchanging part 54 for heat exchanging between the refrigerant and the second cooling end 26 are provided. Further, in a low temperature container wherein a radiant heat shield layer 12 is provided inside a vacuum container 10, cooling is achieved using a refrigeration device of above by thermally connecting the first cooling end 22 to the radiant heat shield layer 12, and by thermally connecting the second cooling end 26 to a superconductive magnet 14 in the radiant heat shield layer 12. |
